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Smoke, flame, critical temperature and rate of temperature rise detector

  • US 3,255,441 A
  • Filed: 11/30/1962
  • Issued: 06/07/1966
  • Est. Priority Date: 11/30/1962
  • Status: Expired due to Term
First Claim
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1. AN ELECTRICAL CIRCUIT COMPRISING:

  • A SOURCE OF REGULATED D.C. VOLTAGE;

    FIRST AND SECOND PHOTOCONDUCTIVE DEVICES CONNECTED IN SERIES ACROSS SAID SOURCE;

    A RESISTANCE LOWER THAN THE DARK RESISTANCE OF SAID FIRST PHOTOCONDUCTIVE DEVICE CONNECTED IN PARALLEL WITH SAID FIRST PHOTOCONDUCTIVE DEVICE;

    A GROUNDED EMITTER, TRANSISTORIZED DIFFERENTIAL AMPLIFIER ELECTRICALLY CONNECTED TO RECEIVE THE VOLTAGE ACROSS SAID SECOND PHOTOCONDUCTIVE DEVICE AS ONE INPUT THERETO;

    A THIRD PHOTOCONDUCTIVE DEVICE CONNECTED IN SERIES WITH A RESISTANCE ACROSS SAID SOURCE, THE VOLTAGE ACROSS SAID THIRD PHOTOCONDUCTIVE DEVICE BEING DIRECTED AS A SECOND INPUT TO SAID DIFFERENTIAL AMPLIFIER;

    MEANS FOR DIRECTING BEAMS OF LIGHT OF CONTROLLED INTENSITY UPON SAID SECOND AND SAID THIRD PHOTOCONDUCTIVE DEVICES;

    A CONTROL-RECTIFIER CONNECTED IN SERIES WITH AN INDICATING CIRCUIT ACROSS SAID SOURCE;

    A TRIGGER ELECTRODE EMBODIED BY SAID CONTROL RECTIFIER;

    MEANS FOR COUPLING THE ELECTRICAL OUTPUT OF SAID DIFFERENTIAL AMPLIFIER TO SAID TRIGGER ELECTRODE;

    CRITICAL TEMPERATURE RESPONSIVE SWITCHING MEANS;

    RATE OF RISE OF TEMPERATURE RESPONSIVE SWITCHING MEANS;

    AND MEANS CONNECTING SAID CRITICAL TEMPERATURE SWITCHING MEANS AND SAID RATE OF RISE OF TEMPERATURE SWITCHING MEANS BETWEEN SAID TRIGGER ELECTRODE AND A SOURCE OF ELECTRICAL ENERGY, WHEREBY CLOSING OF EITHER OF SAID SWITCHING MEANS WILL ENERGIZE SAID TRIGGER ELECTRODE TO RENDER SAID CONTROL RECTIFIER CONDUCTIVE.

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